Electric vehicle braking optimization system based on braking energy recovery

Abstract

The present invention provides an electric vehicle braking optimization system based on brake energy recovery, comprising an electric braking system, a hydraulic braking system, a data acquisition system, and a brake operating system. The data acquisition system's signal output is connected to the electric braking system and the hydraulic braking system. The electric braking system comprises a vehicle domain controller, a motor controller, and a drive motor. S1: Determine braking intent; S2: Execute motor-only braking; S3: Execute motor-hydraulic combined braking. The present invention fully couples the two relatively independent hydraulic and motor braking systems through a chassis domain controller. The ABS / EBD system and the vehicle controller adjust the distribution and adjustment of hydraulic and motor braking forces, fully utilizing motor braking and optimizing energy recovery.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle braking, and in particular to an electric vehicle braking optimization system based on braking energy recovery. Background Art

[0002] When an electric vehicle is in motion, the driver presses the brake pedal, triggering the brake switch and releasing brake pressure from the master cylinder to the wheel bar. Hydraulic braking forces are applied to the front and rear wheels, causing them to brake. When the vehicle controller receives the brake switch activation signal and the battery meets energy recovery requirements, it notifies the MCU to control the motor braking to enter energy recovery mode. When the braking force on the wheel increases to the critical point of the I curve, meaning that the ground adhesion is insufficient to support the braking force and the wheel slip increases, causing locking, the ABS activates and the MCU controls the motor to exit energy recovery mode.

[0003] The aforementioned braking process has the following drawbacks: the electric motor and hydraulic brakes operate as two relatively independent braking control systems. The electric brake force cannot be adjusted in real time, and the combined action of the two systems can cause the rear wheels to lock prematurely, preventing full recovery of braking energy. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides an electric vehicle braking optimization system based on braking energy recovery, which solves the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] The electric vehicle braking optimization system based on braking energy recovery includes: an electric braking system, a hydraulic braking system, and a data acquisition system; the signal output end of the data acquisition system is connected to the electric braking system and the hydraulic braking system; the electric braking system includes a vehicle domain controller, a motor controller, and a drive motor; the vehicle domain controller outputs a torque request to the motor controller, and the motor controller controls the drive motor to perform a driving action or an electric braking action; the output end of the drive motor is connected to the wheel; the hydraulic braking system includes a chassis domain controller, an ABS / EBD module, a hydraulic transmission system, and a brake disc.

[0007] Furthermore, the hydraulic braking system includes a brake pedal and a brake switch. The brake pedal is connected to the brake cylinder and the brake switch through a connecting rod mechanism. The brake switch is bidirectionally connected to the vehicle domain controller and the chassis domain controller.

[0008] Furthermore, the chassis domain controller is connected to the ABS / EBD module via a CAN bus bidirectional communication.

[0009] Furthermore, the hydraulic transmission system includes a brake cylinder, in which a master cylinder pressure sensor is installed, and the master cylinder pressure sensor is bidirectionally connected to the ABS / EBD module and the chassis domain controller via the CAN bus; the output end of the brake cylinder is connected to a proportional valve, and the output end of the proportional valve is connected to multiple pressure regulating valve groups, each pressure regulating valve group corresponds to a wheel, and each wheel is equipped with a brake disc and a wheel speed sensor; the multiple wheel speed sensors and the multiple pressure regulating valve groups are all communicatively connected to the ABS / EBD module.

[0010] Furthermore, the pressure regulating valve group includes a pressure reducing valve and a pressure increasing valve.

[0011] An electric vehicle braking optimization method based on braking energy recovery, the braking optimization method comprising:

[0012] S1. Determine braking intention:

[0013] Determine whether the electric braking force meets the braking requirement;

[0014] If yes, then electric braking alone can meet the braking force requirement and the process goes to S2;

[0015] If not, then the electric brake alone cannot meet the braking force requirement and the process goes to S3;

[0016] S2, execute motor single braking:

[0017] S2.1. The chassis domain controller coordinates the vehicle domain controller and ABS / EBD to couple the hydraulic braking system with the electric braking system.

[0018] S2.2: The chassis domain controller coordinates with the EBD to close the boost valve, preventing the hydraulic brake system from increasing wheel cylinder pressure.

[0019] S2.3. The vehicle domain controller coordinates and controls the electric braking system, switching the motor to energy recovery mode, converting the vehicle's kinetic energy into electrical energy and storing it in the power battery.

[0020] S2.4. The chassis domain controller determines whether the pedaling depth has increased based on the braking signal;

[0021] If not, the current electric braking force can meet the braking force requirement, and the vehicle domain controller controls the electric braking system to keep working;

[0022] If yes, the current electric braking force cannot meet the braking force requirement, and the process goes to S2.5;

[0023] S2.5: The vehicle domain controller controls the electric brake system to increase braking force;

[0024] S2.6. Return to S1;

[0025] S3, execute motor-hydraulic compound braking:

[0026] S3.1. The chassis domain controller coordinates the vehicle domain controller and ABS / EBD to couple the hydraulic braking system with the electric braking system.

[0027] S3.2. The chassis domain controller coordinates and controls the EBD to open the boost valve, causing the hydraulic brake system to increase wheel cylinder pressure. The vehicle domain controller coordinates and controls the operation of the electric brake system, allowing the electric and hydraulic brakes to operate simultaneously.

[0028] Furthermore, S3 also includes:

[0029] S3.3. The chassis domain controller determines, based on the braking signal, whether the drive wheels are likely to lock under the simultaneous application of electric and hydraulic braking forces.

[0030] If yes, then under the synchronous action of electric braking force and hydraulic braking force, there is no tendency for the drive wheels to lock, and the electric braking system and hydraulic braking system remain in operation;

[0031] If not, the drive wheels are likely to lock, and the process goes to S3.4.

[0032] S3.4. The chassis domain controller coordinates with the vehicle domain controller to prioritize gradually disengaging the electric brake and determine whether the locking trend has eased.

[0033] If yes, the locking is relieved and there is no need to activate ABS;

[0034] If not, the locking has not been relieved and the ABS is activated;

[0035] Furthermore, in S1, the specific process of determining whether the electric braking force meets the braking requirement is as follows: the chassis domain controller determines the vehicle's braking intention based on the master cylinder pressure sensor, wheel speed sensor, and pedal travel sensor and calculates the braking requirement resultant force; the vehicle domain controller determines whether the braking energy recovery conditions are met based on the vehicle's driving status information and the power battery's status information, and calculates the maximum electric braking force that can be provided based on the motor speed.

[0036] The present invention provides an electric vehicle braking optimization system based on braking energy recovery. Compared with the prior art, it has the following advantages:

[0037] The chassis domain controller fully couples the two relatively independent systems, the hydraulic braking system and the electric braking system. The ABS / EBD system and the vehicle controller adjust the distribution and adjustment of the hydraulic braking force and the electric braking force to fully utilize the electric braking and optimize energy recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 The schematic diagram of the electric vehicle braking optimization system architecture based on braking energy recovery of the present invention is shown;

[0040] Figure 2 A schematic diagram of the hydraulic brake system architecture of the present invention is shown. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] Combine Figure 1-Figure 2 As shown, the present invention provides an electric vehicle braking optimization method based on braking energy recovery, which includes an electric braking system, a hydraulic braking system, a data acquisition system and a braking operation system; the signal output end of the data acquisition system is connected to the electric braking system and the hydraulic braking system; the electric braking system includes a vehicle domain controller, a motor controller and a drive motor; the vehicle domain controller outputs a torque request to the motor controller, and the motor controller controls the drive motor to perform a driving action or an electric braking action; the output end of the drive motor is connected to the wheel; the hydraulic braking system includes a chassis domain controller, an ABS / EBD module, a hydraulic transmission system, and a brake disc.

[0044] In this embodiment, the hydraulic brake system includes a brake pedal and a brake switch. The brake pedal is connected to the brake cylinder and the brake switch through a connecting rod mechanism. The brake switch is bidirectionally connected to the vehicle domain controller and the chassis domain controller.

[0045] In this embodiment, the chassis domain controller is connected to the ABS / EBD module via a CAN bus bidirectional communication.

[0046] In this embodiment, the hydraulic transmission system includes a brake cylinder, in which a master cylinder pressure sensor is installed. The master cylinder pressure sensor is bidirectionally connected to the ABS / EBD module and the chassis domain controller via the CAN bus; the output end of the brake cylinder is connected to a proportional valve, and the output end of the proportional valve is connected to multiple pressure regulating valve groups, each pressure regulating valve group corresponds to a wheel, and each wheel is equipped with a brake disc and a wheel speed sensor; the multiple wheel speed sensors and the multiple pressure regulating valve groups are all communicatively connected to the ABS / EBD module.

[0047] The chassis domain controller fully couples the two relatively independent systems, the hydraulic braking system and the electric braking system. The ABS / EBD system and the vehicle controller adjust the distribution and adjustment of the hydraulic braking force and the electric braking force to fully utilize the electric braking and optimize energy recovery.

[0048] In this embodiment, the pressure regulating valve group includes a pressure reducing valve and a pressure increasing valve.

[0049] Example 2

[0050] An electric vehicle braking optimization method based on braking energy recovery, the braking optimization method comprising:

[0051] S1. Determine braking intention:

[0052] Determine whether the electric braking force meets the braking requirement;

[0053] If yes, then electric braking alone can meet the braking force requirement and the process goes to S2;

[0054] If not, then the electric brake alone cannot meet the braking force requirement and the process goes to S3;

[0055] S2, execute motor single braking:

[0056] S2.1. The chassis domain controller coordinates the vehicle domain controller and ABS / EBD to couple the hydraulic braking system with the electric braking system.

[0057] S2.2: The chassis domain controller coordinates with the EBD to close the boost valve, preventing the hydraulic brake system from increasing wheel cylinder pressure.

[0058] S2.3. The vehicle domain controller coordinates and controls the electric braking system, switching the motor to energy recovery mode, converting the vehicle's kinetic energy into electrical energy and storing it in the power battery.

[0059] S2.4. The chassis domain controller determines whether the pedaling depth has increased based on the braking signal;

[0060] If not, the current electric braking force can meet the braking force requirement, and the vehicle domain controller controls the electric braking system to keep working;

[0061] If yes, the current electric braking force cannot meet the braking force requirement, and the process goes to S2.5;

[0062] S2.5: The vehicle domain controller controls the electric brake system to increase braking force;

[0063] S2.6. Return to S1;

[0064] S3, execute motor-hydraulic compound braking:

[0065] S3.1. The chassis domain controller coordinates the vehicle domain controller and ABS / EBD to couple the hydraulic braking system with the electric braking system.

[0066] S3.2. The chassis domain controller coordinates and controls the EBD to open the boost valve, causing the hydraulic brake system to increase wheel cylinder pressure. The vehicle domain controller coordinates and controls the operation of the electric brake system, allowing the electric and hydraulic brakes to operate simultaneously.

[0067] In this embodiment, S3 further includes:

[0068] S3.3. The chassis domain controller determines, based on the braking signal, whether the drive wheels are likely to lock under the simultaneous application of electric and hydraulic braking forces.

[0069] If yes, then under the synchronous action of electric braking force and hydraulic braking force, there is no tendency for the drive wheels to lock, and the electric braking system and hydraulic braking system remain in operation;

[0070] If not, the drive wheels are likely to lock, and the process goes to S3.4.

[0071] S3.4. The chassis domain controller coordinates with the vehicle domain controller to prioritize gradually disengaging the electric brake and determine whether the locking trend has eased.

[0072] If yes, the locking is relieved and there is no need to activate ABS;

[0073] If not, the locking is not relieved and the ABS is activated.

[0074] In this embodiment, in S1, the specific process of determining whether the electric braking force meets the braking requirement is as follows: the chassis domain controller determines the vehicle braking intention based on the master cylinder pressure sensor, wheel speed sensor, and pedal travel sensor and calculates the braking requirement resultant force; the vehicle domain controller determines whether the braking energy recovery conditions are met based on the vehicle driving status information and the power battery status information, and calculates the maximum electric braking force that can be provided based on the motor speed.

[0075] In the framework of the present invention:

[0076] The intelligent chassis domain controller determines the vehicle's braking intent and calculates the required braking force based on signals from the master cylinder pressure sensor, wheel speed sensor, and brake switch. Simultaneously, the vehicle controller determines whether the braking energy recovery conditions are met based on the brake pedal position, vehicle driving status, and power battery status, and calculates the maximum electric braking force that can be provided based on the motor speed.

[0077] The ABS / EBD system adjusts the hydraulic braking force of the front and rear wheels through a proportional valve mechanism and a boost valve / reducing valve, and feeds back the four-wheel braking status and hydraulic braking force to the chassis domain controller.

[0078] The intelligent chassis domain control integrates the braking force requirement, the vehicle status and maximum electric braking force size fed back by the vehicle controller, the braking status and hydraulic braking force size fed back by the ABS / EBD system, and other information to calculate the electric braking force size and hydraulic braking force requirement for optimal energy recovery. It also realizes intelligent adjustment of the electric braking force size through the vehicle controller and motor controller, and intelligent adjustment of the hydraulic braking force size through the opening and closing of the ABS+EBD system control valve body, realizing intelligent adjustment of the hydraulic braking and electric braking force by the chassis domain controller, and making full use of motor braking for energy recovery.

[0079] When the vehicle meets the energy recovery conditions and before the wheels lock, the optimized braking control system prioritizes electric motor braking for energy recovery, converting mechanical energy into electrical energy through energy recovery technology and storing it in the power battery. In special situations such as emergency braking, the chassis domain controller controls the simultaneous application of electric and hydraulic braking to ensure driving safety. When the braking force on the wheel exceeds the critical point of the I curve, indicating the beginning of wheel lock, the ABS system is activated and the MCU controls the motor to exit energy recovery mode.

[0080] The optimized braking system coordinates the distribution of motor braking and hydraulic braking through an intelligent domain controller, deeply couples the hydraulic braking system and the motor braking system, and optimizes brake energy recovery.

[0081] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0082] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An electric vehicle braking optimization system based on braking energy recovery is characterized by: Including electric brake system, hydraulic brake system, data acquisition system; The signal output end of the data acquisition system is connected to the electric brake system and the hydraulic brake system; The electric braking system includes a vehicle domain controller, a motor controller, and a drive motor. The vehicle domain controller outputs a torque request to the motor controller, which controls the drive motor to perform driving or electric braking. The output end of the drive motor is connected to the wheels. The hydraulic brake system includes a chassis domain controller, ABS / EBD module, hydraulic transmission system, and brake discs; The hydraulic brake system includes a brake pedal and a brake switch. The brake pedal is connected to the brake cylinder and the brake switch through a connecting rod mechanism. The brake switch is bidirectionally connected to the vehicle domain controller and the chassis domain controller. The hydraulic transmission system includes a brake cylinder, a master cylinder pressure sensor is installed inside the brake cylinder, and the master cylinder pressure sensor is connected to the ABS / EBD module and the chassis domain controller via a CAN bus bidirectional communication; the output end of the brake cylinder is connected to a proportional valve, and the output end of the proportional valve is connected to multiple pressure regulating valve groups, each pressure regulating valve group corresponds to a wheel, and each wheel is equipped with a brake disc and a wheel speed sensor; the multiple wheel speed sensors and multiple pressure regulating valve groups are all connected to the ABS / EBD module via communication; The pressure regulating valve group includes a pressure reducing valve and a pressure boosting valve; The electric vehicle braking optimization method based on braking energy recovery includes the following steps: S1. Determine braking intention: Determine whether the electric braking force meets the braking requirement; If yes, then electric braking alone can meet the braking force requirement and the process goes to S2; If not, then the electric brake alone cannot meet the braking force requirement and the process goes to S3; S2, execute motor single braking: S2.

1. The chassis domain controller coordinates the vehicle domain controller and ABS / EBD to couple the hydraulic braking system with the electric braking system. S2.2: The chassis domain controller coordinates with the EBD to close the boost valve, preventing the hydraulic brake system from increasing wheel cylinder pressure. S2.

3. The vehicle domain controller coordinates and controls the electric braking system, switching the motor to energy recovery mode, converting the vehicle's kinetic energy into electrical energy and storing it in the power battery. S2.

4. The chassis domain controller determines whether the pedaling depth has increased based on the braking signal; If not, the current electric braking force can meet the braking force requirement, and the vehicle domain controller controls the electric braking system to keep working; If yes, the current electric braking force cannot meet the braking force requirement, and the process goes to S2.5; S2.5: The vehicle domain controller controls the electric brake system to increase braking force; S2.

6. Return to S1; S3, execute motor-hydraulic compound braking: S3.

1. The chassis domain controller coordinates the vehicle domain controller and ABS / EBD to couple the hydraulic braking system with the electric braking system. S3.

2. The chassis domain controller coordinates and controls the EBD to open the boost valve, causing the hydraulic brake system to increase wheel cylinder pressure. The vehicle domain controller coordinates and controls the operation of the electric brake system, allowing the electric and hydraulic brakes to operate simultaneously.

2. The electric vehicle braking optimization system based on braking energy recovery according to claim 1, characterized in that; The chassis domain controller is connected to the ABS / EBD module via a CAN bus bidirectional communication.

3. The electric vehicle braking optimization system based on braking energy recovery according to claim 1 is characterized in that: In S3, it also includes: S3.

3. The chassis domain controller determines, based on the braking signal, whether the drive wheels are likely to lock under the simultaneous application of electric and hydraulic braking forces. If yes, then under the synchronous action of electric braking force and hydraulic braking force, there is no tendency for the drive wheels to lock, and the electric braking system and hydraulic braking system remain in operation; If not, the drive wheels are likely to lock, and the process goes to S3.

4. S3.

4. The chassis domain controller coordinates with the vehicle domain controller to prioritize gradually disengaging the electric brake and determine whether the locking trend has eased. If yes, the locking is relieved and there is no need to activate ABS; If not, the locking is not relieved and the ABS is activated.

4. The electric vehicle braking optimization system based on braking energy recovery according to claim 1 is characterized in that: In S1, the specific process of determining whether the electric braking force meets the braking requirement is as follows: the chassis domain controller determines the vehicle's braking intention based on the master cylinder pressure sensor, wheel speed sensor, and pedal travel sensor and calculates the braking requirement resultant force; the vehicle domain controller determines whether the braking energy recovery conditions are met based on the vehicle's driving status information and the power battery status information, and calculates the maximum electric braking force that can be provided based on the motor speed.

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